[Wien] Surface states and slab thickness

[Peter Blaha]

> I just read the email from Peter regarding surface states on the Cu(111) surface. I was wondering If I'm using a correct slab geometry. I have a 10 layer Ge slab (5 layers and mirrored in the z-direction). The reconstructed surface is therefore on both sides of the slab. The vacuum gab is 8 layers thick. Is this suffiecient to calculate surface states or do I need to increase the slab thickness.

Ge is a semiconductor and I don't know if 10 layers are sufficient.
I just know (because I've tested it, see below) that for Cu 7 layers are
not enough.

Do you find TWO bands which correspond to surface states ?

Are they splitted ?

Do another calculation with 12 or 14 layers and compare your results. Once
there is no change, you know that you are converged.

Same procedure applies to the impurities on Cu surface....


                                      P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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